This invention relates to a flow passage structure formed by press-fitting a shaft member into a press-fit bore provided in a flange member so as to be opened at one axial end thereof, and thereby communicating with each other flow passages formed in the flange member and those formed in the shaft member.
Such a flow passage structure is used for a support flange member of a fluid joint, and a support flange of a stator member of a torque converter as disclosed in, for example, Japanese Patent Publication No. 40904/1990. An example of such a related art flow passage structure for a shaft-press-fitted flange member is shown in FIGS. 6 and 7. This structure is formed by press-fitting a shaft member 210 into a press-fit bore 201 of a flange member 200 so as to communicate an oil passage 221 in a housing 220, to which the flange member 200 is fixed, and shaft-side radial bores 212, which are formed in the shaft member 210, with each other via an inside-flange flow passage including flange side radial bores 202 and flange side axial bores 203 which are formed in the flange member 200. The inside-shaft radial bores 212 are joined to axially extending inside-shaft axial bores 211, and these axial bores 211 are jointed to, for example, the interior of a torque converter. This enables the supplying of an oil from the oil passages 221 of the housing 220 to the interior of a torque converter and the discharging of the oil from the latter to the former to be done.
As described above, in the flow passage structure, flange side flow passages are formed of flange side radial bores 202 made so as to extend from an outer circumferential surface of a flange member and through a press-fit bore 201, and flange side axial bores 203 made so as to extend from a side surface of the flange member and communicate with the flange side radial bores 202. The flange side radial bores 202 are closed at the portions thereof which are in the outer circumferential surface of the flange member 200 with plugs 25, or with balls 206 press-fitted thereinto.
Generally speaking, plural flange side flow passages are formed in many cases, and, in such cases, plural flange side radial bores 202 and plural flange side axial bores 203 are formed. These plural flange side radial bores 202 are formed from an axial portion of the flange member so as to extend in the radially outward direction, for example, as shown in FIG. 6. However, such radial bores 202 are formed by drilling, and the indexing of an angular position thereof is required every time one axial bore 203 is formed, so that the processing efficiency (productive efficiency) is low. When the bores 202 extend radially in this manner, the flange side axial bores 203 formed at radially outer end portions of the radial bores 202 are positioned away from one another, and the arrangement of oil passages (oil passages 221 of a housing 220) to which these axial bores 203 are joined, and a hydraulic circuit (for example, a hydraulic control valve) formed on these oil passages is limited. Furthermore, when the flange member of such a construction is fixed to the housing 220, the flange member and housing have to be combined with each other by bolts so that each axial bore 203 is positioned between adjacent bolts as shown in FIG. 7, for the purpose of preventing an oil from leaking from joint surfaces of the flange member and housing. This causes the number of the bolts to increase, a utilizable space to be narrowed, and the weight of the structure to increase.
The present invention has been made in view of the above circumstances, and provides a flow passage structure capable of easily carrying out a drilling operation for the formation of flow passages made of radial bores in a flange member, and arranging axial bores, which are joined to the radial bores, close to one another.
The present invention is directed to a flow passage structure for a shaft-press-fitted flange member (for example, a stator shaft 40 in a mode of embodiment) formed by press- fitting a shaft member (for example, a shaft member 41 in the mode of embodiment) into a press-fit bore (for example, a press-fit bore 141 formed in a flange member 42 in the mode of embodiment), in which the shaft member is provided with first flow passages (for example, oil passages 102 in the mode of embodiment) having openings (for example, right end portions 106 of the oil passages 102 in the mode of embodiment) in an outer circumferential surface thereof, the flange member being provided with plural flow passage-forming bores (for example, oil passages 101 in the mode of embodiment) made from outer circumferential surfaces (for example, outer circumferential surfaces 43b, 43c in the mode of embodiment) thereof so as to extend through the press-fit bore, the shaft member being press-fitted into the press-fit bore so that inner end openings (openings joined to the press-fit bore) of the flow passage-forming bores are opposed to and communicated with openings of the first flow passages, whereby the first and second flow passages are communicated with each other with the plural flow passage-forming bores extending in parallel with one another.
In the case of the flow passage structure formed in this manner, plural flow passage-forming bores extend from the outer circumferential surfaces of the flange member in parallel with each other, so that the indexing of rotational positions during the drilling of the flow passage-forming bores is not needed, i.e., the formation of these bores can be carried out easily. Especially, plural flow passage-forming bores can be formed at once by using plural drills, so that the processing efficiency is high. Since the flow passage-forming bores extend in parallel with each other, the flange-side axial bores communicating therewith can be positioned close to one another, and a hydraulic circuit (for example, a hydraulic control valve) to which these axial bores are connected can be arranged or formed compactly. Furthermore, the fixing of the flange member to a housing can be done by only combining these parts with each other by bolts so that each of the plural axial bores is positioned between adjacent bolts. This enables the number of necessary bolts to be reduced, a space between the joint surfaces of the flange member and housing to be utilized effectively, and the weight of the structure to be reduced.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.